(function (doc, win) {
	  var docEl = doc.documentElement,
		resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
		recalc = function () {
		  var clientWidth = docEl.clientWidth;
		  if (!clientWidth) return;
		  docEl.style.fontSize = 10 * (clientWidth / 320) + 'px';
		};

	  if (!doc.addEventListener) return;
	  win.addEventListener(resizeEvt, recalc, false);
	  doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window);
